Investigation of location, electronic structures, and associated properties of chalcogen atoms adsorbed on silicon surfaces: sulfur and selenium

Abstract

The binding energies of four possible models for sulfur and selenium on the silicon (110) surface have been investigated by the Hartree-Fock cluster procedure. It is concluded that the most likely model for chalcogen atoms adsorbed on this surface is an interchain-bridge model with the adsorbed atom bonded to two atoms on adjacent chains on the surface. This model is shown to provide a Se-Si bond distance of 2.60 Å, in good agreement with the value of 2.55±0.05 Å from x-ray standing-wave measurements. Predictions are made for the ultraviolet photoemission spectra, vibrational frequencies and amplitudes, and nuclear quadrupole interactions associated with the adsorbed sulfur and selenium atoms. The results of the present investigation are shown to explain the intrachain-bridge position observed for tellurium on the silicon (111) surface.